Why not just use more fields? It is limitations like this (and more) that make repeated fields probably not the best choice in this scenario.
I have settled on using buttons - I have 55 of them making up 5 scales with 11 intervals = each is 40 x 20 pixels so they look good on the screen spread out from left to right.
they all execute the same first step script - using a script parameter which indicates which button was pushed (e.g. 511 indicates the 11th button in the 5th scale and so on. Based on this input the script sets one of 5 GV variables 9in a specific table) with a repetition of 11 which allows conditional formatting to change the color fill of the button so it is clear which button in each scale was last pushed. Works well and makes visual sense to people using the app.